The invention relates to an apparatus for checking anaesthesia and ventilation devices, comprising a lung sac arranged between two lobes movable relative to one another, a lung inlet and adjustment means for adjusting the simulation parameters.
Such devices or apparatuses also referred to as “lung simulators” or as “test lung” are used for checking ventilation devices of all kinds and also anaesthesia devices for satisfactory operation before use on humans. The test lungs should if possible be capable of simulating different lung types. The properties of a lung are determined by the parameters resistance (respiratory tract resistance), compliance (hardness of the lungs) and leakage.
In the case of the test lungs used to date, a distinction should be made between two types differing substantially from one another:
Economical conventional test lungs are generally formed by a simple rubber sac (or balloon) which has exactly one resistance (respiratory tract resistance), one compliance (hardness of the lungs) and no leakage. Thus, checking of a ventilation device or anaesthesia device with such test lungs is possible only to an insufficient extent since it is not possible to simulate different lung types therewith. This frequently leads to alleged malfunctions of the device to be tested (e.g. so-called autotriggering), although the lung device to be tested is completely in order.
On the other hand, very complicated and expensive test lungs which operate, for example, by means of a bellows or a cylinder/piston system are disclosed, for example, in DE-A 2 403 616 or DE-A 3 427 182. In the case of such test lungs, the setting of the resistance (i.e. of the respiratory tract resistance) by means of various adapters and the setting of the compliance (i.e. hardness of the lungs) by means of springs or by means of a cylinder/piston system is achieved in fine gradation. Owing to the substantial mechanical design, such test lungs are very heavy, complicated to operate, expensive and generally operable only by means of external energy.